MCQ
The volume of the parallelopiped whose edges are represented by $-12 \hat{i}+\alpha \hat{k}, 3 \hat{j}-\hat{k}$ and $2 \hat{ i }+\hat{ j }-15 \hat{ k }$ is 546 . Then $\alpha=$
  • A
    3
  • B
    2
  • $-3$
  • D
    $-2$

Answer

Correct option: C.
$-3$
(C) Volume of parallelopiped $=\left|\begin{array}{ccc}-12 & 0 & \alpha \\ 0 & 3 & -1 \\ 2 & 1 & -15\end{array}\right|$
$\begin{array}{l}\Rightarrow 546=-12(-45+1)+\alpha(0-6) \\ \Rightarrow \alpha=-3\end{array}$

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